There was a total of about five changes that were necessary to compile KOReader for
riscv64 on Framework Laptop 13 with Deepcomputing RISC-V Mainboard v1
with SiFive U74 RISC-V cores (RVA22). This is a first pass to see if it would compile, so these changes are minimal and will need
be improved.
In the file at base/Makefile.defs: